Xorg compilation issues - source update question

I'm using NetBSD 5-something and currently building from source fails on
dri2proto in external/mit/xorg/include with "nmbmake : Don't know how to
make dri2proto.h". I googled around and this led me to believe that it's
stale dependencies, so I cleared out /usr/obj and /usr/tools and tried
again, with the same results. I suspected that maybe my source trees was
somehow corrupt so I removed the contents of external/mit/xorg, updated the
sources again and tried to build, with the same results.